Deballing drill bit



Feb. 8, 1938.v J, El HALL 2,107,788

' DEBALLING DRILL BIT y Filed Jan. 9, 1937 4 t', Kvk' amr Amen/Tala,xe/YQZZ;

Patented .Feu 8, 1938 UNITED STATES PATENT oFFlcE DEBALLING DRILL BITJesse E. nail, n Angeles, Calif.

Application January 9, 1987, serial No. 119,814 s claims. ',(cl.255-1-71) string from the hole and to then manually rel move theclotted, plastic mass; It will be obvious that this involves the totalloss of the tool'for the full period ofv pulling, cleaning and againlowering the tool, and the expense and the loss of time increasesexactlywith the increase of the depth l of the hole and the involved length ofthe drill string.l

This balling effect is encountered almost regardless of the specifictype of the tool.

It is the broad object of the instant invention to provide a. drillingbit wherein there is provided means the function of which is to actautomatically for eliminationof'packed cuttings or clay.

Further an object isto provide means for rev ducing or eliminating theballing tendency with,-

- little' of a simple character in others, as willbe/ shown -laterherein. Particularly, an object is to provide a de-balling device ofvery simple kind and of readily renewable form, and of low cost' ofmaterial and insta1lation.

40 More specifically, an object of the invention is 'to provide adrilling bit having a, repressible facial area of resilient material soconstructed, arranged-and combined with the bit body as to actautomatically in a rebounding reaction as the A pressure of theformation material is lessened, lin

one way or another, according to the type of bit,.

to eject or loosen up the packing material or clay so that it will fallaway from the bit face; this occurring either while the bit is inrunning contact with the formation forming the bottom of the hole, orwhile the bit is briefly lifted from the bottom, in the case of use offish-tail bits and, if deemed desirable, its rotation ceased for af{very short while for the purpose of slacking ofithe pressure, set upbetween the advancing face of the bit and its normally accumulatedburden of clay.

'The invention consists of certain advancements in the earth bit art asset forth in the ensuing disclosure and having, with ,the above, ad- 5ditional objects and advantages as hereinafter developed, and whoseconstruction, combinations and details -of means, and the manner ofoperation willv be made manifest in the description of the annexed,illustrative embodiment; it being l0 understood that modications,variations and adaptations may be resorted to within the scope,principle and spirit of the invention as more directly claimed in theappendage.

Figure 1 is a side elevation of a conical roller l5 type of bitincluding' the .de-balling feature. t Figure 2 is a transverse sectionof the roller bit in cutting position on the bottom of a hole.

Figure 3 is a cross-section of the blade of a fish-tail type of bitembodying the invention, and 20 Figure 4 is a facial elevation of thesh-tail bit.

form of the de-balling or clay stripping device. 25

In its preferred, form the de-,balling yor clay stripping agent is inthe form of a highly resilient or rebounding, incompressible,non-corrosive, non-metallic, semi-plastic or` mobile character, such,for instance as quite firm rubber; 30 this being readily moldable in'place on the given bits or into properly shaped units for easyapplication thereto in eld tool shops by mechanics of ordinary skill.

' The roller bit of Figs. l and 2 comprises a coni- 35 cal body-2 havingcircumferential rows of spaced teeth 3 of tapered form to providecutting points I. The form oftooth here shown provides an intermediate,transverse, annular back shoulder 5. I'he entire space around thebitbody 2 wlth- 40 in an arbitrary circle C slightly back of the circletouching the points l, Fig. 2, of the relative row of teeth 3 'is lledwith a mass of the desired rebounding agent or rubber 6, which extends,as is .shown in Fig. 1, from end to end of the body 2 45 presenting thespaced rows of teeth 3. The roller is attached in conventional manner tothe lower end of an appropriate, rotating, driven, bit carrier only apart of which is shown at ill.

'I'he points of the roller teeth 3 in the adapta- 50 tion hereillustrated stand out somewhat' from the conical face (circle C) of therubber jacket around the body 2 and during rotation of the carrier i0the points of the teeth are driven into and crack up the formation onthe bottom 55 B of the hole; the roller swinging in a circular orbitabout the axis A of the bit carrier, and turning on its own aial shaftor support 8, iny

the carrier I0. If the teeth 3 penetrate the bottom formation far enoughthe rubber mass 6 thereadjacent will be tangentially repressed andbulged laterally, Fig. 2, with the result that any accumulated layer ofadhesive borings will be ejected from the shallow space around the bedof rubber 6 below the circle of the tooth points B.

It will be seen that there can be no packed accumulation of clay to ballup the space about the roller body 2 within a conical surfaceconstructive about the points of the teeth 3 spaced about and along theconical body 2 of the roller. 'I'he inner face of the rubber, de-ballingjacket 6 is provided with suitable concavities 6a, if needed,

to facilitate the deformation of the incompressible rubber.

Fish-tail bits have flat, forged bodies I5 and the diagonally oppositeand thus advancing faces I6 of this type bit tend to accumulate adhesiveplastic material during the rotation of the bit about its axis with thebottom, sharpened end on the bottom of the earth hole. The de-ballingdevice may be attached to the faces I6 of these bits in any desired ofvarious ways so that a rebounding area of sufficient degree will bepresented and have ample power of reaction'to press back the adherentclay as soon as. the bit has been lifted enough from bottom, and itsrotation stopped if desired, to relieve the clay pack from thecompression force incident to the rotation of the bit. As here shown thefaces I6 are provided with pockets or channels I1, preferably parallelto the axis of the bit and in these channels are arranged andinterlocked therewith bars of rm rubber strippers I 8 whose faces I9stand well outward of the bit faces I6. The backs of the bars orstrippers I8 are concaved at 2 0 to provide for repression of the rubberto some degree under balling pressure of the clay during bit rotation,Fig. 5.

If the bit be stopped and slightly lifted from the bottom o f the hole,back pressure o`f the balling clay will be overcome by the resilience ofthe rubber bars I8 and the layer of clay will drop oi the bit.

If desired the stripper bars I8 may be mounted in backing elements as inthe form of flanged boxes 2| mountable as .a unit in the respectivepockets I'l of the fish-tail bit.

What is claimed is: 1. A self, de-balling, earth-formation, drill bithaving a resilient, re-bounding means whereby to like.

2. An earth'boring drill bit with facial area to reduce or eliminate thetendency of the encountered formation cuttings of balling up on the saidarea of the bit.

3. An earth boring drill bit having cutting portions, and deformative,resilient means mounted on the bit contiguous to said portions andhaving an inherent re-bounding function whereby to destroy the ballingtendency of the plastic cuttings encountered by the operating bit.

4. A toothed roller bit the body of whichl is provided with an elasticand resilient -device mounted thereon between the bit teeth and beyondwhich the tips of the roller teeth project for cutting action; wherebythe rebound of the device acts to overcome or reduce earth-ballingduring action of the bit.

5. A toothed roller bit having a' deformable `automatically dislodgeaccumulated mud or the rubber jacket through which the teeth are exposedat their tips for cutting action; said jacket operative to prevent theballing of earth cuttings between the teeth.

' 6. An earth boring bit-.provided with effective cutting portionsandfacialarea, of the bit, adjacent to the said portions being providedwith deformable, elastic, resilient means having a rebounding functionwhereby to stop balling of clay on said area of the bit.

'1. A bit as set forth in claim 6, and in which said means includesrubbers forming a cushion for the plastic material tending to adhere tothe bit during its rotation.

8. A bit as set forth in claim 6, and in which saidmeans consists of abed of isolated rubber units afxed tothe bit faces.

9. An earth formation, drill bit the surface of which is subjected tobecoming bailed up with clay during drilling operation, is provided witha deformable, resilient means re-boundingly operative to cast off anaccumulated packing of clay or cuttings.

JESSE E. HALL.

